Providing registration for passwordchallenge authentication includes receiving an access code or pattern inputted by a user, recording a time message associated with each component of the access code or pattern via a processor, generating a data record in combining each component of the access code or pattern with the associated time message, and storing the data record. The microwave oven includes an outer cabinet defining an outer appearance of the wall-mounted type microwave oven, and an inner cabinet disposed in the outer cabinet with a predetermined spacing therebetween. By computing a signal andor noise level for a number of available configurations, the electrodes resulting in the highest signal-to-noise ratio may be selected for use by the device. In the structure sidewalls of the top portion of the DTI and sidewalls of the STI are comprised of doped, re-crystallized silicon.